diff --git a/Source/Core/Core/HW/DSP.cpp b/Source/Core/Core/HW/DSP.cpp
index 650c35e1d0..3952133748 100644
--- a/Source/Core/Core/HW/DSP.cpp
+++ b/Source/Core/Core/HW/DSP.cpp
@@ -453,7 +453,7 @@ void RegisterMMIO(MMIO::Mapping* mmio, u32 base)
                  MMIO::InvalidWrite<u16>());
 
   // 32 bit reads/writes are a combination of two 16 bit accesses.
-  for (int i = 0; i < 0x1000; i += 4)
+  for (u32 i = 0; i < 0x1000; i += 4)
   {
     mmio->Register(base | i, MMIO::ReadToSmaller<u32>(mmio, base | i, base | (i + 2)),
                    MMIO::WriteToSmaller<u32>(mmio, base | i, base | (i + 2)));
diff --git a/Source/Core/Core/HW/ProcessorInterface.cpp b/Source/Core/Core/HW/ProcessorInterface.cpp
index bf4cb29f17..37c10580bd 100644
--- a/Source/Core/Core/HW/ProcessorInterface.cpp
+++ b/Source/Core/Core/HW/ProcessorInterface.cpp
@@ -142,7 +142,7 @@ void RegisterMMIO(MMIO::Mapping* mmio, u32 base)
                  MMIO::InvalidWrite<u32>());
 
   // 16 bit reads are based on 32 bit reads.
-  for (int i = 0; i < 0x1000; i += 4)
+  for (u32 i = 0; i < 0x1000; i += 4)
   {
     mmio->Register(base | i, MMIO::ReadToLarger<u16>(mmio, base | i, 16),
                    MMIO::InvalidWrite<u16>());
diff --git a/Source/Core/Core/HW/VideoInterface.cpp b/Source/Core/Core/HW/VideoInterface.cpp
index 6e7780857d..5cc8a174d2 100644
--- a/Source/Core/Core/HW/VideoInterface.cpp
+++ b/Source/Core/Core/HW/VideoInterface.cpp
@@ -433,7 +433,7 @@ void RegisterMMIO(MMIO::Mapping* mmio, u32 base)
                  }));
 
   // Map 8 bit reads (not writes) to 16 bit reads.
-  for (int i = 0; i < 0x1000; i += 2)
+  for (u32 i = 0; i < 0x1000; i += 2)
   {
     mmio->Register(base | i, MMIO::ReadToLarger<u8>(mmio, base | i, 8), MMIO::InvalidWrite<u8>());
     mmio->Register(base | (i + 1), MMIO::ReadToLarger<u8>(mmio, base | i, 0),
@@ -441,7 +441,7 @@ void RegisterMMIO(MMIO::Mapping* mmio, u32 base)
   }
 
   // Map 32 bit reads and writes to 16 bit reads and writes.
-  for (int i = 0; i < 0x1000; i += 4)
+  for (u32 i = 0; i < 0x1000; i += 4)
   {
     mmio->Register(base | i, MMIO::ReadToSmaller<u32>(mmio, base | i, base | (i + 2)),
                    MMIO::WriteToSmaller<u32>(mmio, base | i, base | (i + 2)));